Until now, the rock crushing machine was me and a mortar and pestle.
But now, whoo boy, things are about to get serious. Rob ordered a prospector’s rock crusher while he was still working overseas. It has been patiently waiting in the box for him to get home. Once he had a chance to see the crusher and decide what kind of pulleys would work with the motor, we went out to scrounge the hardware stores for the rest of the materials he needed.
First, he wanted to build a cart to hold it all. He’s been working on it over the past week or two, with a delay or two. The welder switch went out. Then the oxygen for his cutting torch ran dry, and the metal-cutting saw didn’t work as planned… it never seems to fail that to get a step forward, there are always a few steps backwards first. I know it frustrates him.
He fabricated a table on wheels to hold the crusher and motor. He also made a spot for me to slide in a bowl to catch the ground up rock. It drops from the crusher through a hole in the cart’s top shelf. In one of his previous lives, Rob was a welder, so he did a fantastic job on this little custom cart on wheels.
Then came time to wire the motor so it could actually be plugged into an outlet. I didn’t even realize it didn’t come with a plug, so I’m glad Rob also knew how to do that. He put a handy switch right on the cart (didn’t know it would need that, either). Plus, he made a place to put the cord when the crusher is not in use.
Testing the Rock Crusher
Until the shroud is done for the pulleys, I probably won’t use it, but we did test a rock to see how it would work. I can’t wait to do more, but one of the hardest rocks for me to work with is, surprisingly, limestone. It’s very hard to break and takes a while to grind. Plus, I can’t use stainless steel because the gray comes off into the stone. So I wanted to know right away if I’d be able to use this metal crusher to grind limestone. It isn’t a ‘one and done’ process.
The starting rocks have to be broken to 3/4″ pieces first. This is the step that usually results in blood (mine). So I’ll occasionally offer libations of blood for stones. Once the stone is broken, Rob took the honor of running the maiden batch while I recorded video. It’s going to be a little while before I can upload the video. Our internet is still at a crawl these days. But we ran it through the crusher at a few different settings, starting with the most coarse. Each time through, he tightened the bolt to put the crusher jaws closer together. In the end, we had a coarse crushed stone.
I believe 50 mesh is the best it will do, which is good enough. At the very least it makes the rest of the crushing a lot easier. Or I can just go with that to the washing and settling part of the process.
The finest crush we ended with was still too coarse to make paint, but fine enough to wash the pigment. Then I can use the lighter sediment to make paint. This is what I’ve been doing anyway, once I crushed it enough in the mortar and pestle. The rock crusher just makes it a lot easier to crush a larger batch of rocks. This in turn will make it easier for me to get bigger batches of paints. Or even just pigment powder to have on hand for making paint. I’ll also be able to sell finer pigments more often. Right now I hardly have any left after making my own paints. So the shop shelves have been pretty bare in paint or pigment offerings. I’ll remedy that soon, though.